Traditional wireless telecommunications antenna such as quarterwave monopole antenna, half wave dipole antenna, helical antenna, spiral antenna and the like usually include a input antenna terminal and a ground antenna terminal. The ground antenna terminal is connected to a wireless telecommunication common (ground) and a input terminal of the antenna is connected to the telecommunication device's input or output or both. In case a same antenna is used to concurrently receive and transmit signals operating at relatively similar frequencies, a dedicated circuit (diplexer) is used to fulfil the purpose of isolating the input and the output of the telecommunication device while selectively coupling the input and output signal from and to the antenna's input terminal.
In case the same antenna and same active terminal are used to alternately receive or transmit signals in simplex mode, a selective switching system is used for the purpose of alternate coupling and isolation. In both cases described above, the antenna itself is approximately resonant at both transmit and receive frequencies and therefore both frequencies must be approximately the same. When the transmit signal and the receive signal are significantly different in frequency, the use of a diplexer or switching circuit may be impractical and uneconomical for certain applications due to the unnecessary circuitry components and space required.